This invention relates to combiner rails for installation on opposite sides of a container-transporting conveyor system. The function of the combiner rails is to reduce a relatively wide span of multiple containers to a single row or file of the containers. More particularly, the invention relates to combiner rails each having rollers in a staggered pattern that virtually eliminates nesting between adjacent rollers. As a result, jamming of containers between the combiner rails and excessive roller impact wear are avoided.
In industrial installations, there are many places where combiner rails are used. For example, combiner rails may be installed in a bottling plant at each location where a wide accumulation of bottles must be reduced to a single file. There can be a number of such locations in a single bottling plant conveyor system. As containers are conveyed between the combiner rails, jamming of containers can occur when a plurality of the containers, usually two, arrive at the same restricted area simultaneously and are squeezed and jammed between converging combiner rails.
In an effort to solve the jamming problem, combiner rails that incorporate a series of rollers have been developed. In this roller combiner rail construction, a plurality of longitudinally spaced shafts are provided on vertical axes in a common plane. One or more rollers of equal diameter are mounted in a vertical tier on each shaft. To reduce the depth of gaps between the rollers on adjacent shafts, the rollers on one shaft are spaced from one another and are staggered from the rollers on an adjacent shaft, allowing the two tiers of rollers to overlap. Even with this overlapping roller arrangement, the radial projections of the rollers limit how close the shafts can be to one another. Therefore, even though the gaps between rollers are reduced by this overlapping roller arrangement, these gaps are still wide and deep enough to receive segments of containers.
As a container moves along the combining rail, it can be guided into one of these gaps and to escape the gap, the container cannot be blocked from moving away from the gap. When two containers simultaneously enter gaps on opposing combiner rails they become wedged together and jammed. The pressure of the large number of conveyors behind the jammed containers prevents the jammed containers from escaping the recesses to relieve the jam. When such jamming occurs, the jammed containers must be broken free manually often requiring shut down of the conveyor system. In any event, the jamming interrupts the plant production.
In addition to the jamming problem, the rollers in conventional combining rails are subject to wear from impact with containers. These impact blows occur as a container lurches from one gap to the next one. Each time a container enters a gap, it collides with the surface of the roller immediately downstream of the gap. Repetition of these impacts produces wear on the rollers and decreases the useful life of the combiner rail.